V and o primer disc detector



J. P. ROESING V AND O PRIMER DISC DETECTOR July 18, 1961 Filed Nov. 3, 1959 R mg #M N m 1 g M m 1 7 e n a v 1 2 m\ flw2, w sail/w 4 d. s 2 g z/zrwa v I P 2 fin 8 M A RIQ 6 5 6 United States Patent Filed Nov. 3', 1959, Ser. No. 850,747 3 Claims. (CI. 86-10) This invention relates to a cellulose disc detector, and more particularly to a detecting device designed to detect the presence or absence of a cellulose disc in the primer pocket of a 20 mm. cartridge case.

In order to comply with Ordnance specifications, a cellulose disc must be inserted in the primer pocket of av 20 mm. cartridge case prior to the insertion of the primer, per se. Inasmuch as the absence of a disc is considered a major defect, a positive meats of determining the presence of the disc in the primer pocket is necessary. In order to make certain that all 20 mm. primed cases have the cellulose disc inserted, the present invention was designed to detect the presence or absence of these discs.

The present invention has for a primary object a mechanism for use in priming machines that will make certain that all 20 mm. primed cartridge cases have a cellulose disc inserted therein before the priming operation begms.

It is another object of the invention to provide a mechanism operated by compressed air to detect the presence of a cellulose disc in a cartridge. primer chamber, and when such disc is absent, the air pressure in the mechanism will drop and stop the operating mechanism.

Another object is to provide a device which is simple in construction yet positive and eflicient in operation.

The specific nature of the invention as well as other objects and advantages thereof, will clearly appear from a description of a preferred embodiment as shown in the accompanying drawings in which:

FIG. 1 is a vertical section of the detector of the invention at rest and showing the cartridge case with an inserted disc.

FIG. 2 is a similar view of the detector in its operating position.

Referring more particularly to the drawing wherein like reference characters designate like or corresponding parts throughout the different views, 1 indicates the ram of a priming machine (not shown) which moves up and down to locate the detecting mechanism into and out of operating position with respect to the cartridge case. 2 indicates the detecting device of the invention in its entirety, and 3 indicates a cartridge case supported on a dial pin 4 of the priming machine (not shown). The cartridge case 3 is provided with the conventional primer chamber 5 in its base while 6 denotes the cellulose disc resting in chamber 5.

The detecting mechanism 2 is fixed in the ram 1 for travel therewith and consists of a cylinder 7 having a bore 8 which is internally threaded as at 9 to receive a cylinder cap 10 in threadable engagement therewith. The cylinder 7 is provided with a pair of elongated vertical bores 11 in its wall port-ion. Bores 11 communicate with the bore 8 through upper and lower radial parts 12 and 13 respectively. Cylinder cap 10 is centrally bored as at 14 to form a chamber and is radially bored and internally threaded as at 15 to receive a threaded nipple 16 of an air hose 17. Home 15 and chamber 14 intercommunicate through a port 18.

A piston assembly is indicated generally at 19 and comprises a piston 20 which is slidable in bore 8 of cylinder 7 and is axially bored as at 21. At its upper end, bore 21 is counterbored and threaded as at 22 and re ceives the threaded end of a rod '23 which extends up Patented July 18, 1961 through a counter bore 24 and is provided with a head 25 to prevent piston 20 from falling out of bore 8. Sealing means are provided and consists of upper and lower O-rings 26 and 27 in piston 20 seal-ing between piston 20 and the wall of bore 8, and O-ring 28 sealing between rod 23 and bore 24.

Piston 20 is further provided with an annular reduced portion 29 near its upper end and radial ports 30 provide air passageways between annular space 29 and bore 21.

Piston- 20 is further provided with an externally threaded end 31. A punch 32 is provided with an axial bore 33 and an external flange 34 at its upper end. Punch 32 is held in abutting relation with piston 20 by a threaded cap nut 35 and flange 34 so that bores 33 and 21 are in axial alignment. A rubber pad 36 is cemented in a bore 37 of cap 35.

Operation At the start of the detecting cycle, the ram 1 on the v machine (not shown) is at the top of its stroke (FIG.

l) and a cartridge case 3 is supported upside down on a dial pin 4 directly below the detecting unit 2 with a cellulose disc 6 in the primer pocket 5 that has been drilled by the priming machine (not shown) at a preceding station, also not shown. Air pressure supplied through hose 17 enters cylinder 7 at approximately 25 p.s.i. holds the piston assembly 19 in a downward. position. As the ram 1 moves down, the detecting unit 2 is carried with it until the ram 1 reaches a point that is approximately /2" from bottom dead center, at which point the rubber pad 36 around the punch 32 comes in contact with the head of cartridge case 3, as seen in FIG. 2. As ram 1 continues through its last /2 of downward travel, piston 20 becomes stationary, resting on the head of cartridge case 3 and [the cylinder 7 continues to move downward with ram 1. As soon as the top O-ring 27 on the piston leaves the bottom port on the cylinder, air moves into the radial ports 30 in the piston 20, on down through axial bore 21 in piston 20, and is sealed at the bottom of the vertical bore 21 by cellulose disc 6. This results in an equal pressure throughout the system. If a disc 6 is not present and over the usual flash hole 38 of the cartridge, the air pressure in the system will drop to approximately 10 pounds, depending on the pre-set indicating mechanism, usually employed in the priming machine, not shown herein, an illustrative example of such mechanism being shown in U.S. patent to Wills, No. 659,724, thereby stopping the machine, not shown, at the top of the same stroke. This allows the cartridge case to be removed or a disc to be placed in the primer pocket by hand.

Afiter the last /2 of the downward stroke has been completed, ram 1 starts upward moving cyliner 7. The piston 20 remains stationary due to the air pressure on the head of the piston until the first /2 of the upward travel is completed, at which time, the top O-ring 27 will be in line with the lower ports 13 in cylinder 7 and seals off the air pressure to the ports 30 in the piston 20, thereby maintaining approximately 25 p.s.i. on the system. The ram 1 continues its upward travel with the piston 20 and cylinder 7 in a fixed relation with each other, thus completing the cycle.

While a preferred form of the invention has been shown and described, various modifications and substitutions of equivalents will occur to those skilled in the art aiiter a study of the foregoing disclosure. Hence, the disclosure should be taken in an illustrative rather than a limiting sense, and it is the desire and intention to reserve all modifications within the scope of the subjoined claims.

What is claimed is:

1. In combination, a cartridge case having a primer pocket, a cellulose disc in said pocket, a primer disc detecting unit fixed in the ram arm of a detecting machine for determining the presence of said cellulose disc in said priming pocket of said cartridge case comprising a cylinder having an axial bore therein, a pair of elongated vertical bores in its wall thereof, and a pair of upper and lower radial ports communicating between said vertical bores and said axial bore in said cylinder, a cap having a central bore and a counter bore for detachable closing of the upper end of said cylinder, an air supply hose threadably engaging said cap and in communication with said central bore in said cap for supplying air pressure to said cylinder, a piston slidably mounted in said axial bore in said cylinder, said piston defining an annular reduced portion near its upper end thereof and having an axial bore, there being radial ports in said piston, said ports communicating with said reduced portion and said axial bore in said piston, an upper sealing ring carried by the upper portion of said piston and disposed above said annular reduced portion, said upper sealing ring normally closing said lower radial ports in said cylinder when said detecting unit is in an inoperative position, a lower sealing ring carried by said piston and disposed below said annular reduced portion, a guide rod detachably connected at its lower end to the upper portion of said piston and slidably extending through said cap, and a resilient sealing means carried by the lower end of said piston, said last named sealing means abutting the base of a cartridge case to be tested in said unit when said unit is carried downward by said ram arm and said upper sealing ring uncovers said lower radial ports in said cylinder upon continuing downward motion of said ram arm whereby air pressure from said air hose is permitted to enter the upper portion of said cylinder, said upper, elongated and lower ports in said cylinder, into said reduced annular portion, radial ports and axial bore of said piston and become increased in said detection unit when sealed therein by a said disc when present in said primer pocket of said cartridge case, and upon absence of a said disc in said pocket, said air pressure escapes through said cartridge case.

2. In a device as claimed in claim 1, wherein said sealing means on said piston comprises, a punch having an external annular flange at its upper end and a central bore therein, said punch being disposed in axial abutting relation with the bottom face of said piston whereby said axial bore in said piston coincides with said central bore in said punch, a retaining cap having an annular internal flange adapted for threadable engagement with the lower end of said piston whereby said internal flange in said retaining cap will engage under said external flange on said punch to hold said punch in said abutment with said piston and a resilient pad encircling said punch fixed in said cap.

3. A primer disc detector including, in combination, a cartridge case having a primer pocket therein, and a cellulose disc in said pocket, a device for detecting the presence of said disc when present in said pocket, comprising a cylinder fixed to a ram arm of a detecting machine, said cylinder having an axial bore therein, an air supply in communication with the upper end of said axial bore, a pair of elongated vertical bores in the wall thereof and upper and lower radial bores communicating between said vertical bores and said axial bore in said cylinder, a piston defining an annular reduced portion near the upper end thereof, said piston being slidable in said axial bore, said piston having an axial bore therein, said last named bore being closed at its upper end and open at its lower end, and radial bores in said piston providing communication between said axial bore in said piston and said reduced portion in said piston, the upper portion of said piston normally closing said lower radial bore in said cylinder wall when said piston is in its inoperative position, said cylinder and said piston being adapted to be moved downwardly by the aforesaid ram arm when testing for the presence of said disc in said pocket, whereby the lower end of said piston contacts the base of the cartridge case and upon continued downward movement of said cylinder, said lower radial bore in said cylinder is uncovered and air from said air supply is permitted to enter the upper portion of said axial bore, in said cylinder, said upper radial bores, said vertical bores and said lower radial bores in said cylinder wall and into said reduced portion, said radial bores and said axial bore in said piston, and, when said disc is present in said pocket, said air will be built up in said cylnder and said piston, and upon absence of said disc in said pocket, the air pressure will be relieved through said primer pocket in the cartridge case and be lowered in said cylinder and said piston.

References Cited in the file of this patent UNITED STATES PATENTS 181,364 Salisbury et al. Aug. 22, 1876 639,432 Pondorf Dec. 19, 1899 659,724 Wills Oct. 16, 1900 1,589,080 Kyle June 15, 1926 1,692,771 Ferris Nov. 20, 1928 2,185,402 Dinzl Jan. 2, 1940 2,325,642 Turnock et a1 Aug. 3, 1943 

